Oxygen is essential for aerobic metabolism and sustaining organ function. Hypoxia is harmful. So in theory, more should be better. However, when it comes to oxygen therapy, more is not necessarily better as we do not normally exist in hyperoxygenated state and oxygen therapy is not without harm. Hyperoxia could lead to vasoconstriction, free radical generation and consequent tissue damage and denitrogenation of the lungs with resulting atelectasis and de-recruitment.
Therefore, the efforts are on to find the balance for oxygenation targets. Various trials have yielded conflicting results for optimal oxygen target for ARDS. The National Heart, Lung, and Blood Institute ARDS Clinical Trials Network had recommended a target PaO2 between 55 mm Hg and 80 mm Hg. However, in a recent multicenter randomized, liberal, or conservative oxygen therapy for acute respiratory distress syndrome trial…
